Favolaschia rotundipora Q. Y. Zhang, H. Zhao & Y. C. Dai 2026, sp. nov.

Favolaschia rotundipora Q. Y. Zhang, H. Zhao & Y. C. Dai sp. nov. Fig. 3 Type. China, Hainan Province, National Park of Hainan Tropical Rainforest, Jianfengling, dead bamboo culm, 18.699491, 108.869944, elevation: 755 m, 12 Jul 2026, collected by Heng Zhao, Dai 40361 (BJFC 065184, holotype). Etymology. “ Rotundipora ” (Lat.): refers to the species having round pores. Macrostructures. Basidiomata annual, gregarious, gelatinous when fresh and dry. Pilei 3–7 × 2–5 mm, reniform, flabelliform, semicircular or elliptical; pileal surface white to pale gray when fresh, light gray upon drying, convex with a reticulate pattern matching the pores below, faintly pruinose when dry; margin straight, entire; context thin. Hymenophore paler than pileal surface, grayish-white when fresh and off-white when dry, poroid, about 17–90 pores per basidiomata; mature pores 0.6–1.5 mm diam., rounded, larger near the base and smaller near the edge, the marginal pores often incomplete; tubes up to 0.2 mm long. Stipe present or absent, paler than pileal surface, laterally attached, short, tapering to a slightly swollen base, 0–2.5 mm. Microstructures. Basidiospores (5.6 –) 6–8.9 (– 9.2) × (4.5 –) 4.7–7.5 (– 7.6) µm, L = 7.44 μm, W = 5.82 μm, Q = 1.27–1.29 (n = 60 / 2), broadly ellipsoid, hyaline, thin-walled, smooth, with one big or some small guttules, faintly IKI +, CB –. Basidia 22–36 × 8–12 μm, barrel-shaped to pyriform, often tapering gradually toward the base, with some guttules, 2–4 – spored, sterigmata 4–9 μm long; basidioles subclavate or pyriform, slightly smaller than basidia. Gloeocystidia and acanthocystidia absent. Pileipellis hyphae interwoven, smooth to diverticulate, thin-walled, swollen, up to 8.0 µm diam.; terminal cells cystidioid or irregularly tubular, flexuous, with constrictions or diverticulate projections on the sides and at the apex. Tramal hyphae subparallel along tubes, widely spaced in a gelatinous matrix, occasionally with dense contents, thin-walled, 2–4 μm diam. Hyphae in stipe parallel along stipe, some swollen, slightly thick-walled, 2–5 µm diam. Clamp connections present. Additional specimen examined. China, Hainan Province, National Park of Hainan Tropical Rainforest, Limushan, dead bamboo culm, 19.165119, 109.750721, elevation: 623 m, 15 Jul 2026, collected by Heng Zhao, Dai 40362 (BJFC 065185). Distribution and ecology. Favolaschia rotundipora is distributed in tropical area of Hainan Province, China; it grows on dead bamboo and causes a white rot.